Glide parachute



Sept 24, 1963 T. w. KNACKE ETAL 3,104,857

GLIDE PARACHU TE Filed sept. 1. 1961 4 sheets-sheet 1 'Sept 24, 1963 T.w. KNAcKE ETAL 3,104,857

GLIDE PARACHUTE Filed sept. 1, 19.61

4 Sheets-Sheet 2 -T. w. KNACKE ETAL 3,104,857

GLIDE PARACHUTE Filed sept. 1, 1961 4 sneets-sheef s 1%/ Pi? j @mlm/lmSept- 24, 196s T. w. KNACK.; Em. 3,104,851

" `GLIDE: PARACHUTE Filed Sept. l, 1961 4 Sheets-Sheet 4 -chutes havevbeen used in .the past.

United States Patent O 35.613357 GLDE PARACHU in Theodore W. naclrc, LosAngeles, and .lohn H. McCiow,

fir., Torrance, Calii., assignors, hy mesne assignments,

to Itek Corporation, Lexington, Mass., a corporation of Delaware FiledSept. 1, 1961, Ser. No. 135,6@3 8 Claims. (Cl. 24d-M5) The presentinvention relates to parachutes, and it relates more particularly to lanew and improved type of parachute having the ability to glide along adetermined COuISS.

Glide parachutes, per se, are known, and such parari'he wellknown typesof prior art glide parachutes include those designated the HartParatchute, the Derrick Parachute, the Tojo Parachute, and differenttypes of blank-gore parachutes.

The prior art glide parachutes referred to in the preceding paragraphall operate on Ithe sante principle of reaction forces. ln these priorart glide parachutes, one or more openings are provided in the canopyiof the parachute, and the air escaping through these openings createsreaction forces which propels the parachute in a direction opposite tothe direction of the escaping air.

Unlike the prior Iart glide parachutes mentioned above, the glideparachute of the present invention uses the principle of lift mainly,`but combines reaction for directional control, as will be described.The glide parachute of the invention is constructed to have the shapeand characteristics of an air foil, in that it is shaped to obtain alift force on its surface from the atmosphere through which is moves.

As `is well known, lift is the for-ce which counteracts gravity, andthis force is caused iby the motion of air over and under an air foil asit moves through the atmosphere. Lift is produced, as enunciated by theBernoulli priciple, because :the air foil is shaped such that the speed'of air over its top surface is greater than the speed of air over itslower surface. To achieve this condition, the top surface of the airfoil is curved, and the air has a further path to travel over the topsurface than over the lower surface. This, in accordance with Bernoullisprinciple, creates a condition such that the pressure `of air below theair foil is greater than the pressure of air above, and -this pressuredierential causes the air foil to rise or lift.

As is also well known, drag is the force which resists the forwardmotion of an object through the air. A first type of drag of an air foilsection, known -as prole drag, depends largely on the shape of the airfoil. Another type of drag is directly caused by the lift and is calledinduced drag. The total drag of the air foil is the combination of theprofile drag and the induced drag.

The improved glide parachute of the present invention is constructed tohave an air foil coniiguration, and the glide characteristics thereofare produced by a combination oi lift and drag, rather than by drag andreaction forces as is the case in the prior tart type Iof glideparachutes referred to above.

An object of the invention, therefore, is to provide an improved type ofglide parachute which is capable of gliding along a determined glidepath.V

, Another object is to provide such an improved type of glide parachutewhich is capable of gliding along the determined glide path with a highdegree of directional stability. This object is achieved, for example,in a second embodiment of the invention yby the provision of one or morestabilizing fins.

Yet another object is to provide such an improved type 2V of glideparachute which is capable of being guided along a desired glide path.This latter object is achieved, for example, in a further embodiment bythe provision of controllable vents in the canopy of the parachute, orpockets, as will be described.

Other objects and advantages will become apparent from a considerationof the following speciiicaition in conjunction with the accompanyingdrawings, in which:

FIGURE l is a iside sectional View of a parachute constructed inaccordance with one embodiment of the invention to have an air foilconfiguration;

FIGURE 2 is a top View of the assembly of FIGURE 1 and illustrating theparticular plane configuration of the canopy;

FIGURES 3 and 4 represent other suitable plane configurations for thecanopy;

FIGURE 5 is a schematic representation of the parachute of FIGURE 1 andillustrating the forces involved in the assembly;

FIGURE 6 is a side elevational View of a parachute similar to theparachute of "FIGURE 1 and which incudes a stabilizing iin formed in thecanopy of the paracute;

FIGURE 7 is a top plan View FIGURE 6;

FEGURE 8 is a top plan view of a parachute constructed in accordancewith the concepts of the invention and further including controllablesteering vents in the canopy;

FGURE 9 is a side View `of the parachute of FiGURE 8, substantially onthe line 9--9 of FIGURE 8;

FlGURE 10 is an end view of the parachute substantially on t-he linelik-ld of FIGURE 9;

FIGURES 11 and 12 are top plan view of a parachute constructed inaccordance with the concepts of the invention and further includingcontrollable steering pockets in the canopy;

FiGURE 13 is a top plan view of a parachute constructed in accordancewith the concepts of the invention and including controllable steeringmeans; and

FIGURE 14 is a side View of the parachute of HG- URE 13.

As shown, for example, in FGURES 1 and 2,l the parachute of the firstembodiment of the invention includes a canopy lli. The canopy lil is'shaped to have an air foil coniiguration, as best shown in `)FIGURE 1,when the parachute is in an inflated condition. The canopy 1li achievesthe air foil configuration in the embodiment of FIGURES l and 2, byappropriately shaping the canopy andl by turning in its peripheral rimportion towards the open underside of the air foil section formedthereby. v

lIt will lbe apparent fro-rn an examination of the presentation ofFIGURE 1, that the cross-section through the parachute is similar to athick air foil with a high camber and an open underside. The camber may,for example, be of the order of 10%.

The air foil shape may be maintained, [for example, by internal andexternal anchor lines, such as the'anchor lines 12 'od FIGURES 1 and 2and by ,gusset-like ribs 1d, as shown in FIGURE l. The anchor lines 12and the members 14 maintain a `desired balance between aerodynamic andstress forces. A tension line may also of the parachute of be providedat the Ilower opening to keep the proper tension on all parts of theparachute. y

A plurality of suspension :lines lo are secured to the canopy at angularpositions around the periphery thereof. yIn the embodiment 'of FIGURE l,these suspension lines 16 are spaced radially outwardly from the innerperipheral edge of the turned in rirn portion, so that the 3 anchorlines 12 may maintain the canopy in its air foil shape.

The canopy It) may be self-inilarting; or it may include inflatabletubes or inilation rigging for the purpose of preventing deflation orflutter olf parts of the canopy, or to maintain the desired airfoilshape of the canopy.

The material used tor the canopy should preterably be of low porosity.However, any suitable amaterial, such as onganic textiles, synthetictextiles, plastics, glass lber, wire mesh and the like, may be used. Asillustrated in FIGURE 1, an appropriate load I8 is suspended from thelower zend of the suspension lines 16.

The `embodiment of the invention shown in FIGURES 1 and 2 has a canopylwihose plane configuration resembles an ellipse on one side of atransverse axis X--X, and a parabola on the other side, as shown in FIG-URE 2.

As shown in FIGURES 3 and 4, the canopy may have other plane rforms. Forexample, the canopy 10a in FIGURE 3 has a circular-shaped plane -formgand the canopy 19h of FIGURE 4 has an oval plane form. The plane torniolf the canopy may have any other appropriate comii'guration.

As shown in FIGURE 5, as the parachute of FIGURE 1 moves through theatmosphere, various forces are created. First there is the downwardforce, as represented by the vector Weight created by the force olf:grav-ity =on the ioad 18. The resulting motion or the parachute throughthe atmosphere cneates a li-ft force, due to the air (foil shape of thecanopy 16. This lift tforce is represented by the vector lift in thediagram of FIGURE 5. The resultant of the two yforces weight and liftcauses the assembly to move along the path designated glide pa Motionalong the glide path is opposed by the drag lforce discussed above. Thislatrter torce is represented by the vector drag in FIG- URE 5. Anexamination 'of FIGURE 5 will reveal, therefore, that the glideparachute assembly of the present invention, instead of proceedingdirectly downwardly towards earth, is caused to move along a particularglide path during its downward descent.

rIhe parachute of FIGURES 6 and 7 is similar in most respects to theglide parachute of FIGURE l. The parachute of -FIGURE 6 includes acanopy lilo which may have a conliguration similar to any of thecanopies described above. A plurality of suspension lines 16e suspend aload 18o iirom the canopy 10c. During the downward descent :of theparachute of IFIGURE 6, the parachute is caused to glide along the pat-hindicated by the arrow in FIGURE 6.

As a iurther tfeature of the embodiment of the invention shown inFIGURES 6 and 7; `one or more fins, such as the extension, or iin, 22 isformed on the canopy 10c. The iin 22 protrudes from the canopy asillustrated in FIGURES l6 and 7. This iin has a tubular configuration,and it communicates with the interior yof the canopy 10c. 'Ilhe fin 22is inflated by the ram pressure inside the parachute. A small exit hole22a may be provided at the end .ott the extension 22.

The cross-section of the tubular iin 22 may be circular, oval,polygonal, or `other suitable shape. One or more ot the lns, such as theiins 22 in FIGURES 6 fand 7 may be provided. These ns extend irom therear of the canopy in a direction opposite to the direction of ight. Thepurpose of the tins is to provide the rglide parachute with directionalstability, and hold its glide path in the direction ot the wind.

The parachute illustrated in FIGURES S-lO is sirnilar in most respectsto the parachute embodiments described above. The latter parachuteincludes a canopy 10d ot any desired plane form and coniigured as an airtoil in accordance with the teachings of the invention.

'Ille parachute of FIGURES 8-l0 includes a plurality of suspension lines16d. -In this embodiment, the suspension lines are shown as attached tothe turned-in A inner rim of the canopy. The canopy itself is cut andconiigured to have its air foil shape when inated.

The parachute of FIGURES 8 10 4is provided with a pair of vents 36 and32. These vents are positioned on opposite sides o the canopy 10d, asshown. The vents 3d and 32 function as a steering means Ifor theparachute to cause it to glide down along a desined path.

'llhe steering vent 39 is provided with a control line 34 which extendsdown through a ring 36 to a position where it can be manipulated by aperson suspended trom the parachute. 'Ilhe steering vent 32 is,likewise, provided with a control line 38 which extends down through aring 4G .to a position Where it also can be manipulated by the person.

The manipulation of the control lines 34 and 38 causes the cowl portionsof cthe vents 30 and 32 to be moved in and out with respect to thecanopy. This, in turn, controls the cross-section area of the vents andthe amount of air passing therethrough. 'Ihis control of the air passagecontrols the reaction forces so that effective steering olf theparachute may be realized.

The parachute of yFIGURES 11 and l2 is pro/vided with controllableair-brake pockets for steering purposes. 'Ihese pockets are designated50 and 52 in FIGURES 1l and l2. The pockets are positioned on oppositesides of the canopy 19e of the parachute, and they open in the`direction of lglide, as shown. The pockets inflate as the parachuteproceeds along its glide path; and act as air brakes.

The amount of opening of the individual pockets is controlled by lines54 and 56. 'Ihese lines, like the lines 34 and 38 in FIGURES 8, 9 and10, run through appropriately positioned rings 58 and 60 and down to aposition in which they can be manipulated by the person suspended from.the parachute. The pockets 50 and 52 in FIGURE ll are shown in theopen, inflated position. The pockets in FIGURE 12 are shown closed,under the control tof the lines 54 and 56. Y

When the left pocket 50 alone is opened, the parachute will be caused toturn to the left. On the other hand, when the righ-t pocket 52 alone isopened, the parachute will be caused to turn to the right. Opening bothpockets 50 land 52 will air brake the forward motion of the parachuteand change its glide slope. A n

The parachute of FIGURES 13 and 14 `includes a canopy 107 which has anairfoil configuration in accordance with the teachings of the invention.The parachute of FIGURES 13 and 14 also includes a plurality ofsuspension lines 66.

A first group 62 of the suspension lines 60 is connected` to a riser 64.A second group 66 of the suspension lines 60 isfconnected to a riser 68.A third group 70 of thev suspension lines is connected to a riser 72. Azfourth group 74 of the suspension lines is connected to a riser 76, notshown.

Additional fixed risers may be used for Aother groups of the suspensionlines, if so desired. The risers 64, 68, 72, 76, however, arecontrollable in that they may be lengthened or shortened. If the riser68, for example, is lengthened and the riser 76 is shortened, the canopy10i will execute a right hand bank and the parachute will turn right.

Likewise, if the riser 68 is shortened and the riser 76 is lengthened,the canoyp 10f will execute a left bank and the parachute will turnleft. On the other hand, if the riser 72 is lengthened and the riser 64is shortened, or vice versa, the pitch of the canopy will change and aglide path control is provided.

The risers illustrated in FIGURE 14 provide, there- Y of the inventionis advantageous in that it is constructed to glide with a high degree ofdirectional stability along a glide path in its descent to earth, andwhich in some of its embodiments is capable of ya full convenientattitude control.

While particular embodiments of the invention have been shown anddescribed, it is evident that modifications may .be made. The presentinvention is intended to cover all such modiiicat-i'ons as fall withinthe spirit and scope of the invention.

What is claimed is:

1. A deployable glide parachute assembly comprising:

an upper exible inilated canopy member having a circumferential edge;

a lower, dish shaped member, partially enclosing the underside of thecanopy member, having an inner peripheral edge deiining an aperture andhaving `an outer peripheral edge attached t-o the circumferential edgeofthe canopy member;

when deployed, the parachute assembly generating an air foil congurationwith leading and trailing edges having a predetermined camber line in apl'ane lof symmetry extending between the leading and trailing edges;

the distance between the canopy member and the lower member normal tothe camber line land in the plane of symmetry continuously increasing ata first rate from the leading edge to a maximum intermediate the leadingand trailing edges and thereafter decreasing at a second rate -to thetrailing edge;

means extending between the inner peripheral edge :of the lower memberand the canopy to maintain the air ifoil conguration when the parachuteis deployed; and

a plurality |of suspension lines secured to the canopy at spaced angularpositions disposed about the perimeter of the canopy for supporting aload.

2. The parachute assembly of claim 1 wherein the means for maintainingthe air foil configuration further comprises gusset-like ribs, one endof which is connected to the lower member and the other end of which isoonnected to the load bearing suspension lines.

3. The parachute assembly of claim 1 wherein the canopy furthercomprises at least one extension projecting therefrom rfor providingdirectional stability along the glide path ofthe parachute.

4. The parachute assembly iof claim 3 wherein the ex-Y tension has atubular iin-like configuration and is initiated by the ram pressureinside the canopy.

5. The parachute assembly of claim 1 wherein the canopy member furthercomprises at least one vent formed therein to control the movement Kofthe parachute along its glide path.

6. The parachute assembly of claim 5 wherein the canopy has at least apair of vents formed therein to control the movement of the parachute-along its glide path;

each of the vents having la cowl associated therewith;

land

a corresponding pair of control lines attached to respective ones of theoowls to control the passage of air through the vents therebycontrolling the movement of the parachute along its glide path.

7. "Bhe parachute assembly of claim 1 wherein the canopy furthercomprises at least a pair of pockets attached thereto at diametricallyyopposite positions and opening in the Adirection of movement of theparachute to control the movement lort the parachute along its glidepath.

8. The parachute assembly of claim 7 further including a -pair of[control lines attached to respective ones Of the pockets to control:the amount of opening of the pockets.

References Cited in the file of this patent UNITED STATES PATENTS1,270,419 Kendig June 25, 1918 1,780,190 Hoffman Nov. 4, 1930 2,318,674Coleman May 11, 1943 2,562,799 Kowalski July 31, 1951 2,804,276 HutsonAug. 27, 1957 2,941,765 Feldman June 21, 1960 2,993,668 Gold July 25,1961 3,013,753 Hughes et al. Dec. 19, 1961 FOREIGN PATENTS 144,792 GreatBritain yJune 17, l1920 585,513 France Dec. 10, 1924 240,341 SwitzerlandApr. 16, 1946 9,948 Germany Aug. 21, 1956 756,139 Great Britain Aug. 29,1956 OTHER REFERENCES Aviation Week Magazine, pages 57, 59, 63, Sept.19, 1960.

1. A DEPLOYABLE GLIDE PARACHUTE ASSEMBLY COMPRISING: AN UPPER FLEXIBLEINFLATED CANOPY MEMBER HAVING A CIRCUMFERENTIAL EDGE; A LOWER, DISHSHAPED MEMBER, PARTIALLY ENCLOSING THE UNDERSIDE OF THE CANOPY MEMBER,HAVING AN INNER PERIPHERAL EDGE DEFINING AN APERTURE AND HAVING AN OUTERPERIPHERAL EDGE ATTACHED TO THE CIRCUMFERENTIAL EDGE OF THE CANOPYMEMBER; WHEN DEPLOYED, THE PARACHUTE ASSEMBLY GENERATING AN AIR FOILCONFIGURATION WITH LEADING AND TRAILING EDGES HAVING A PREDETERMINEDCAMBER LINE IN A PLANE OF SYMMETRY EXTENDING BETWEEN THE LEADING ANDTRAILING EDGES; THE DISTANCE BETWEEN THE CANOPY MEMBER AND THE LOWERMEMBER NORMAL TO THE CAMBER LINE AND IN THE PLANE OF SYMMETRYCONTINUOUSLY INCREASING AT A FIRST RATE FROM THE LEADING EDGE TO AMAXIMUM INTERMEDIATE THE LEADING AND TRAILING EDGES AND THEREAFTERDECREASING AT A SECOND RATE TO THE TRAILING EDGE; MEANS EXTENDINGBETWEEN THE INNER PERIPHERAL EDGE OF THE LOWER MEMBER AND THE CANOPY TOMAINTAIN THE AIR FOIL CONFIGURATION WHEN THE PARACHUTE IS DEPLOYED; ANDA PLURALITY OF SUSPENSION LINES SECURED TO THE CANOPY AT SPACED ANGULARPOSITIONS DISPOSED ABOUT THE PERIMETER OF THE CANOPY FOR SUPPORTING ALOAD.